Purines, pyrimidines, and imidazoles. Part XXV. Some chemical reactions and interconversions of intermediates in the sequence of biosynthesis de novo of purine nucleotides leading to imidazole nucleotides
作者:M. Franks、Colin P. Green、G. Shaw、Graeme J. Litchfield
DOI:10.1039/j39660002270
日期:——
anhydride, and α-amino-N′-cyclohexylacetamidine was rapidly reconverted into 5-amino-1-cyclohexylimidazole with ethyl formimidate hydrochloride in a buffered aqueous solution. The structures of all the intermediates were confirmed by alternative syntheses from glycine or aminoacetonitrile. A similar sequence of reactions has been observed with the corresponding 5-amino-1-β-D-ribofuranosyl imidazole-4-carboxylic
5-氨基-1-环己咪唑-4-羧酸的受控弱酸处理逐步导致形成5-氨基-1-环己咪唑,N'-环己基-α-甲酰基氨基乙am,α-氨基-N'-环己基乙am(或在较高的pHα- ñ -formylamino- ñ '-cyclohexylacetamide),并且还以更高的pH值,α氨基ñ '-cyclohexylacetamide。通过用甲酸-乙酸酐和α-氨基-N进行甲酰化,可以很容易地逆转去甲酰基化反应在缓冲水溶液中,用甲酸亚氨基乙酯盐酸盐将'-环己基乙am迅速转化为5-氨基-1-环己咪唑。所有中间体的结构均通过甘氨酸或氨基乙腈的交替合成得到证实。已经观察到与相应的5-氨基-1-β- D-核呋喃糖基咪唑-4-羧酸5'-磷酸相似的反应顺序,并讨论了该结果在生物合成途径演变方面的可能意义。 。